sys/vfs/umapfs/umap_vnops.c

   1 /*
   2  * Copyright (c) 1992, 1993
   3  *      The Regents of the University of California.  All rights reserved.
   4  *
   5  * This code is derived from software donated to Berkeley by
   6  * the UCLA Ficus project.
   7  *
   8  * Redistribution and use in source and binary forms, with or without
   9  * modification, are permitted provided that the following conditions
  10  * are met:
  11  * 1. Redistributions of source code must retain the above copyright
  12  *    notice, this list of conditions and the following disclaimer.
  13  * 2. Redistributions in binary form must reproduce the above copyright
  14  *    notice, this list of conditions and the following disclaimer in the
  15  *    documentation and/or other materials provided with the distribution.
  16  * 3. All advertising materials mentioning features or use of this software
  17  *    must display the following acknowledgement:
  18  *      This product includes software developed by the University of
  19  *      California, Berkeley and its contributors.
  20  * 4. Neither the name of the University nor the names of its contributors
  21  *    may be used to endorse or promote products derived from this software
  22  *    without specific prior written permission.
  23  *
  24  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  25  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  26  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  27  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  28  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  29  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  30  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  31  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  32  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  33  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  34  * SUCH DAMAGE.
  35  *
  36  *      @(#)umap_vnops.c        8.6 (Berkeley) 5/22/95
  37  * $FreeBSD: src/sys/miscfs/umapfs/umap_vnops.c,v 1.30 1999/08/30 07:08:04 bde Exp $
  38  * $DragonFly: src/sys/vfs/umapfs/Attic/umap_vnops.c,v 1.2 2003/06/17 04:28:43 dillon Exp $
  39  */
  40
  41 /*
  42  * Umap Layer
  43  */
  44
  45 #include <sys/param.h>
  46 #include <sys/systm.h>
  47 #include <sys/kernel.h>
  48 #include <sys/sysctl.h>
  49 #include <sys/vnode.h>
  50 #include <sys/mount.h>
  51 #include <sys/namei.h>
  52 #include <sys/malloc.h>
  53 #include <sys/buf.h>
  54 #include <miscfs/umapfs/umap.h>
  55 #include <miscfs/nullfs/null.h>
  56
  57 static int umap_bug_bypass = 0;   /* for debugging: enables bypass printf'ing */
  58 SYSCTL_INT(_debug, OID_AUTO, umapfs_bug_bypass, CTLFLAG_RW,
  59         &umap_bug_bypass, 0, "");
  60
  61 static int      umap_bypass __P((struct vop_generic_args *ap));
  62 static int      umap_getattr __P((struct vop_getattr_args *ap));
  63 static int      umap_inactive __P((struct vop_inactive_args *ap));
  64 static int      umap_lock __P((struct vop_lock_args *ap));
  65 static int      umap_print __P((struct vop_print_args *ap));
  66 static int      umap_reclaim __P((struct vop_reclaim_args *ap));
  67 static int      umap_rename __P((struct vop_rename_args *ap));
  68 static int      umap_unlock __P((struct vop_unlock_args *ap));
  69
  70 /*
  71  * This is the 10-Apr-92 bypass routine.
  72  * See null_vnops.c:null_bypass for more details.
  73  */
  74 static int
  75 umap_bypass(ap)
  76         struct vop_generic_args /* {
  77                 struct vnodeop_desc *a_desc;
  78                 <other random data follows, presumably>
  79         } */ *ap;
  80 {
  81         struct ucred **credpp = 0, *credp = 0;
  82         struct ucred *savecredp = 0, *savecompcredp = 0;
  83         struct ucred *compcredp = 0;
  84         struct vnode **this_vp_p;
  85         int error;
  86         struct vnode *old_vps[VDESC_MAX_VPS];
  87         struct vnode *vp1 = 0;
  88         struct vnode **vps_p[VDESC_MAX_VPS];
  89         struct vnode ***vppp;
  90         struct vnodeop_desc *descp = ap->a_desc;
  91         int reles, i;
  92         struct componentname **compnamepp = 0;
  93
  94         if (umap_bug_bypass)
  95                 printf ("umap_bypass: %s\n", descp->vdesc_name);
  96
  97 #ifdef DIAGNOSTIC
  98         /*
  99          * We require at least one vp.
 100          */
 101         if (descp->vdesc_vp_offsets == NULL ||
 102             descp->vdesc_vp_offsets[0] == VDESC_NO_OFFSET)
 103                 panic ("umap_bypass: no vp's in map");
 104 #endif
 105
 106         /*
 107          * Map the vnodes going in.
 108          * Later, we'll invoke the operation based on
 109          * the first mapped vnode's operation vector.
 110          */
 111         reles = descp->vdesc_flags;
 112         for (i = 0; i < VDESC_MAX_VPS; reles >>= 1, i++) {
 113                 if (descp->vdesc_vp_offsets[i] == VDESC_NO_OFFSET)
 114                         break;   /* bail out at end of list */
 115                 vps_p[i] = this_vp_p =
 116                         VOPARG_OFFSETTO(struct vnode**, descp->vdesc_vp_offsets[i], ap);
 117
 118                 if (i == 0) {
 119                         vp1 = *vps_p[0];
 120                 }
 121
 122                 /*
 123                  * We're not guaranteed that any but the first vnode
 124                  * are of our type.  Check for and don't map any
 125                  * that aren't.  (Must map first vp or vclean fails.)
 126                  */
 127
 128                 if (i && (*this_vp_p)->v_op != umap_vnodeop_p) {
 129                         old_vps[i] = NULL;
 130                 } else {
 131                         old_vps[i] = *this_vp_p;
 132                         *(vps_p[i]) = UMAPVPTOLOWERVP(*this_vp_p);
 133                         if (reles & 1)
 134                                 VREF(*this_vp_p);
 135                 }
 136
 137         }
 138
 139         /*
 140          * Fix the credentials.  (That's the purpose of this layer.)
 141          */
 142
 143         if (descp->vdesc_cred_offset != VDESC_NO_OFFSET) {
 144
 145                 credpp = VOPARG_OFFSETTO(struct ucred**,
 146                     descp->vdesc_cred_offset, ap);
 147
 148                 /* Save old values */
 149
 150                 savecredp = (*credpp);
 151                 if (savecredp != NOCRED)
 152                         (*credpp) = crdup(savecredp);
 153                 credp = *credpp;
 154
 155                 if (umap_bug_bypass && credp->cr_uid != 0)
 156                         printf("umap_bypass: user was %lu, group %lu\n",
 157                             (u_long)credp->cr_uid, (u_long)credp->cr_gid);
 158
 159                 /* Map all ids in the credential structure. */
 160
 161                 umap_mapids(vp1->v_mount, credp);
 162
 163                 if (umap_bug_bypass && credp->cr_uid != 0)
 164                         printf("umap_bypass: user now %lu, group %lu\n",
 165                             (u_long)credp->cr_uid, (u_long)credp->cr_gid);
 166         }
 167
 168         /* BSD often keeps a credential in the componentname structure
 169          * for speed.  If there is one, it better get mapped, too.
 170          */
 171
 172         if (descp->vdesc_componentname_offset != VDESC_NO_OFFSET) {
 173
 174                 compnamepp = VOPARG_OFFSETTO(struct componentname**,
 175                     descp->vdesc_componentname_offset, ap);
 176
 177                 compcredp = (*compnamepp)->cn_cred;
 178                 savecompcredp = compcredp;
 179                 if (savecompcredp != NOCRED)
 180                         (*compnamepp)->cn_cred = crdup(savecompcredp);
 181                 compcredp = (*compnamepp)->cn_cred;
 182
 183                 if (umap_bug_bypass && compcredp->cr_uid != 0)
 184                         printf(
 185                     "umap_bypass: component credit user was %lu, group %lu\n",
 186                             (u_long)compcredp->cr_uid,
 187                             (u_long)compcredp->cr_gid);
 188
 189                 /* Map all ids in the credential structure. */
 190
 191                 umap_mapids(vp1->v_mount, compcredp);
 192
 193                 if (umap_bug_bypass && compcredp->cr_uid != 0)
 194                         printf(
 195                     "umap_bypass: component credit user now %lu, group %lu\n",
 196                             (u_long)compcredp->cr_uid,
 197                             (u_long)compcredp->cr_gid);
 198         }
 199
 200         /*
 201          * Call the operation on the lower layer
 202          * with the modified argument structure.
 203          */
 204         error = VCALL(*(vps_p[0]), descp->vdesc_offset, ap);
 205
 206         /*
 207          * Maintain the illusion of call-by-value
 208          * by restoring vnodes in the argument structure
 209          * to their original value.
 210          */
 211         reles = descp->vdesc_flags;
 212         for (i = 0; i < VDESC_MAX_VPS; reles >>= 1, i++) {
 213                 if (descp->vdesc_vp_offsets[i] == VDESC_NO_OFFSET)
 214                         break;   /* bail out at end of list */
 215                 if (old_vps[i]) {
 216                         *(vps_p[i]) = old_vps[i];
 217                         if (reles & 1)
 218                                 vrele(*(vps_p[i]));
 219                 };
 220         };
 221
 222         /*
 223          * Map the possible out-going vpp
 224          * (Assumes that the lower layer always returns
 225          * a VREF'ed vpp unless it gets an error.)
 226          */
 227         if (descp->vdesc_vpp_offset != VDESC_NO_OFFSET &&
 228             !(descp->vdesc_flags & VDESC_NOMAP_VPP) &&
 229             !error) {
 230                 if (descp->vdesc_flags & VDESC_VPP_WILLRELE)
 231                         goto out;
 232                 vppp = VOPARG_OFFSETTO(struct vnode***,
 233                                  descp->vdesc_vpp_offset, ap);
 234                 if (*vppp)
 235                         error = umap_node_create(old_vps[0]->v_mount, **vppp, *vppp);
 236         };
 237
 238  out:
 239         /*
 240          * Free duplicate cred structure and restore old one.
 241          */
 242         if (descp->vdesc_cred_offset != VDESC_NO_OFFSET) {
 243                 if (umap_bug_bypass && credp && credp->cr_uid != 0)
 244                         printf("umap_bypass: returning-user was %lu\n",
 245                             (u_long)credp->cr_uid);
 246
 247                 if (savecredp != NOCRED) {
 248                         crfree(credp);
 249                         (*credpp) = savecredp;
 250                         if (umap_bug_bypass && credpp && (*credpp)->cr_uid != 0)
 251                                 printf(
 252                                     "umap_bypass: returning-user now %lu\n\n",
 253                                     (u_long)(*credpp)->cr_uid);
 254                 }
 255         }
 256
 257         if (descp->vdesc_componentname_offset != VDESC_NO_OFFSET) {
 258                 if (umap_bug_bypass && compcredp && compcredp->cr_uid != 0)
 259                         printf(
 260                             "umap_bypass: returning-component-user was %lu\n",
 261                             (u_long)compcredp->cr_uid);
 262
 263                 if (savecompcredp != NOCRED) {
 264                         crfree(compcredp);
 265                         (*compnamepp)->cn_cred = savecompcredp;
 266                         if (umap_bug_bypass && credpp && (*credpp)->cr_uid != 0)
 267                                 printf(
 268                             "umap_bypass: returning-component-user now %lu\n",
 269                                     (u_long)compcredp->cr_uid);
 270                 }
 271         }
 272
 273         return (error);
 274 }
 275
 276
 277 /*
 278  *  We handle getattr to change the fsid.
 279  */
 280 static int
 281 umap_getattr(ap)
 282         struct vop_getattr_args /* {
 283                 struct vnode *a_vp;
 284                 struct vattr *a_vap;
 285                 struct ucred *a_cred;
 286                 struct proc *a_p;
 287         } */ *ap;
 288 {
 289         short uid, gid;
 290         int error, tmpid, nentries, gnentries;
 291         u_long (*mapdata)[2], (*gmapdata)[2];
 292         struct vnode **vp1p;
 293         struct vnodeop_desc *descp = ap->a_desc;
 294
 295         error = umap_bypass((struct vop_generic_args *)ap);
 296         if (error)
 297                 return (error);
 298
 299         /*
 300          * Umap needs to map the uid and gid returned by a stat
 301          * into the proper values for this site.  This involves
 302          * finding the returned uid in the mapping information,
 303          * translating it into the uid on the other end,
 304          * and filling in the proper field in the vattr
 305          * structure pointed to by ap->a_vap.  The group
 306          * is easier, since currently all groups will be
 307          * translate to the NULLGROUP.
 308          */
 309
 310         /* Find entry in map */
 311
 312         uid = ap->a_vap->va_uid;
 313         gid = ap->a_vap->va_gid;
 314         if (umap_bug_bypass)
 315                 printf("umap_getattr: mapped uid = %d, mapped gid = %d\n", uid,
 316                     gid);
 317
 318         vp1p = VOPARG_OFFSETTO(struct vnode**, descp->vdesc_vp_offsets[0], ap);
 319         nentries =  MOUNTTOUMAPMOUNT((*vp1p)->v_mount)->info_nentries;
 320         mapdata =  (MOUNTTOUMAPMOUNT((*vp1p)->v_mount)->info_mapdata);
 321         gnentries =  MOUNTTOUMAPMOUNT((*vp1p)->v_mount)->info_gnentries;
 322         gmapdata =  (MOUNTTOUMAPMOUNT((*vp1p)->v_mount)->info_gmapdata);
 323
 324         /* Reverse map the uid for the vnode.  Since it's a reverse
 325                 map, we can't use umap_mapids() to do it. */
 326
 327         tmpid = umap_reverse_findid(uid, mapdata, nentries);
 328
 329         if (tmpid != -1) {
 330
 331                 ap->a_vap->va_uid = (uid_t) tmpid;
 332                 if (umap_bug_bypass)
 333                         printf("umap_getattr: original uid = %d\n", uid);
 334         } else
 335                 ap->a_vap->va_uid = (uid_t) NOBODY;
 336
 337         /* Reverse map the gid for the vnode. */
 338
 339         tmpid = umap_reverse_findid(gid, gmapdata, gnentries);
 340
 341         if (tmpid != -1) {
 342
 343                 ap->a_vap->va_gid = (gid_t) tmpid;
 344                 if (umap_bug_bypass)
 345                         printf("umap_getattr: original gid = %d\n", gid);
 346         } else
 347                 ap->a_vap->va_gid = (gid_t) NULLGROUP;
 348
 349         return (0);
 350 }
 351
 352 /*
 353  * We need to process our own vnode lock and then clear the
 354  * interlock flag as it applies only to our vnode, not the
 355  * vnodes below us on the stack.
 356  */
 357 static int
 358 umap_lock(ap)
 359         struct vop_lock_args /* {
 360                 struct vnode *a_vp;
 361                 int a_flags;
 362                 struct proc *a_p;
 363         } */ *ap;
 364 {
 365
 366         vop_nolock(ap);
 367         if ((ap->a_flags & LK_TYPE_MASK) == LK_DRAIN)
 368                 return (0);
 369         ap->a_flags &= ~LK_INTERLOCK;
 370         return (null_bypass((struct vop_generic_args *)ap));
 371 }
 372
 373 /*
 374  * We need to process our own vnode unlock and then clear the
 375  * interlock flag as it applies only to our vnode, not the
 376  * vnodes below us on the stack.
 377  */
 378 int
 379 umap_unlock(ap)
 380         struct vop_unlock_args /* {
 381                 struct vnode *a_vp;
 382                 int a_flags;
 383                 struct proc *a_p;
 384         } */ *ap;
 385 {
 386         vop_nounlock(ap);
 387         ap->a_flags &= ~LK_INTERLOCK;
 388         return (null_bypass((struct vop_generic_args *)ap));
 389 }
 390
 391 static int
 392 umap_inactive(ap)
 393         struct vop_inactive_args /* {
 394                 struct vnode *a_vp;
 395                 struct proc *a_p;
 396         } */ *ap;
 397 {
 398         struct vnode *vp = ap->a_vp;
 399         struct umap_node *xp = VTOUMAP(vp);
 400         struct vnode *lowervp = xp->umap_lowervp;
 401         /*
 402          * Do nothing (and _don't_ bypass).
 403          * Wait to vrele lowervp until reclaim,
 404          * so that until then our umap_node is in the
 405          * cache and reusable.
 406          *
 407          */
 408         VOP_INACTIVE(lowervp, ap->a_p);
 409         VOP_UNLOCK(ap->a_vp, 0, ap->a_p);
 410         return (0);
 411 }
 412
 413 static int
 414 umap_reclaim(ap)
 415         struct vop_reclaim_args /* {
 416                 struct vnode *a_vp;
 417         } */ *ap;
 418 {
 419         struct vnode *vp = ap->a_vp;
 420         struct umap_node *xp = VTOUMAP(vp);
 421         struct vnode *lowervp = xp->umap_lowervp;
 422
 423         /* After this assignment, this node will not be re-used. */
 424         xp->umap_lowervp = NULL;
 425         LIST_REMOVE(xp, umap_hash);
 426         FREE(vp->v_data, M_TEMP);
 427         vp->v_data = NULL;
 428         vrele(lowervp);
 429         return (0);
 430 }
 431
 432 static int
 433 umap_print(ap)
 434         struct vop_print_args /* {
 435                 struct vnode *a_vp;
 436         } */ *ap;
 437 {
 438         struct vnode *vp = ap->a_vp;
 439         printf("\ttag VT_UMAPFS, vp=%p, lowervp=%p\n", vp, UMAPVPTOLOWERVP(vp));
 440         return (0);
 441 }
 442
 443 static int
 444 umap_rename(ap)
 445         struct vop_rename_args  /* {
 446                 struct vnode *a_fdvp;
 447                 struct vnode *a_fvp;
 448                 struct componentname *a_fcnp;
 449                 struct vnode *a_tdvp;
 450                 struct vnode *a_tvp;
 451                 struct componentname *a_tcnp;
 452         } */ *ap;
 453 {
 454         int error;
 455         struct componentname *compnamep;
 456         struct ucred *compcredp, *savecompcredp;
 457         struct vnode *vp;
 458
 459         /*
 460          * Rename is irregular, having two componentname structures.
 461          * We need to map the cre in the second structure,
 462          * and then bypass takes care of the rest.
 463          */
 464
 465         vp = ap->a_fdvp;
 466         compnamep = ap->a_tcnp;
 467         compcredp = compnamep->cn_cred;
 468
 469         savecompcredp = compcredp;
 470         compcredp = compnamep->cn_cred = crdup(savecompcredp);
 471
 472         if (umap_bug_bypass && compcredp->cr_uid != 0)
 473                 printf(
 474             "umap_rename: rename component credit user was %lu, group %lu\n",
 475                     (u_long)compcredp->cr_uid, (u_long)compcredp->cr_gid);
 476
 477         /* Map all ids in the credential structure. */
 478
 479         umap_mapids(vp->v_mount, compcredp);
 480
 481         if (umap_bug_bypass && compcredp->cr_uid != 0)
 482                 printf(
 483             "umap_rename: rename component credit user now %lu, group %lu\n",
 484                     (u_long)compcredp->cr_uid, (u_long)compcredp->cr_gid);
 485
 486         error = umap_bypass((struct vop_generic_args *)ap);
 487
 488         /* Restore the additional mapped componentname cred structure. */
 489
 490         crfree(compcredp);
 491         compnamep->cn_cred = savecompcredp;
 492
 493         return error;
 494 }
 495
 496 /*
 497  * Global vfs data structures
 498  */
 499 /*
 500  * XXX - strategy, bwrite are hand coded currently.  They should
 501  * go away with a merged buffer/block cache.
 502  *
 503  */
 504 vop_t **umap_vnodeop_p;
 505 static struct vnodeopv_entry_desc umap_vnodeop_entries[] = {
 506         { &vop_default_desc,            (vop_t *) umap_bypass },
 507         { &vop_getattr_desc,            (vop_t *) umap_getattr },
 508         { &vop_inactive_desc,           (vop_t *) umap_inactive },
 509         { &vop_lock_desc,               (vop_t *) umap_lock },
 510         { &vop_print_desc,              (vop_t *) umap_print },
 511         { &vop_reclaim_desc,            (vop_t *) umap_reclaim },
 512         { &vop_rename_desc,             (vop_t *) umap_rename },
 513         { &vop_unlock_desc,             (vop_t *) umap_unlock },
 514         { NULL, NULL }
 515 };
 516 static struct vnodeopv_desc umap_vnodeop_opv_desc =
 517         { &umap_vnodeop_p, umap_vnodeop_entries };
 518
 519 VNODEOP_SET(umap_vnodeop_opv_desc);